“It draws attention to the fact that biased regional media have immediately, as if on command, begun an aggressive information attack, laying all the responsibility on the government,” Lukashevich said in a statement on Wednesday.

The Russian Foreign Ministry, citing its sources, said that a homemade rocket carrying unidentified chemical substances had been launched from an area controlled by the opposition.

“A homemade rocket with a poisonous substance that has not been identified yet – one similar to the rocket used by terrorists on March 19 in Khan al-Assal - was fired early on August 21 [at Damascus suburbs] from a position occupied by the insurgents,” Lukashevich said.

Earlier on Wednesday, conflicting reports emerged of recent chemical weapons use in Syria. This comes on the same day that the UN inspectors arrive in Damascus to investigate allegations of use of toxic arms. The casualty figures range from dozens to almost 1,300 deaths.

The Russian diplomat stated that it seems as though it was “a provocation planned in advance.” The “criminal action” near Damascus coincided with the beginning of UN experts’ work in Syria - which speaks in favor of such a conclusion.

Lukashevich pointed out that similar reports about Syrian authorities allegedly using chemical weapons have popped up before. However, the information has never been confirmed.

In Moscow’s view, the latest possible “provocation” might be the opposition’s attempt to get support from the UN Security Council and undermine the Geneva peace talks on Syria.

Russia believes the incident should be thoroughly investigated by professionals. It urged everyone who has influence on armed extremists to do everything possible to finally put an end to such provocations involving chemical poisonous substances.

Meanwhile, Washington said it has no independent verification about the use of chemical weapons in Syria. The US is planning to consult the UN Security Council about the allegations, Principal Deputy Press Secretary Josh Earnest told reporters, as cited by Reuters.

The chief UN chemical weapons investigator Ake Sellstrom is currently discussing the alleged chemical attack with the Syrian government. The organization’s Secretary General Ban Ki-moon was shocked by the report of the alleged attack, his press office said.

The UK, one of the five permanent members of the body, will demand that the UN team of investigators gets “unrestricted access” to the area of the alleged attack, Foreign Secretary William Hague told reporters.

If reports are verified, it would mark “a shocking escalation” of the use of chemical weapons in Syria,” he said, adding that “we are determined the people responsible will one day be held to account.”

The Syrian government has no information regarding opposition forces using chemical weapons in the Damascus area, the country’s information minister told RT Arabic. Omran Al-Zoubi mentioned that the pro-Assad army has suffered no losses because of such weapons. He did not rule out, however, that the poisonous substances could have been used against civilians – as was the case in the Khan al-Assal incident outside Aleppo, in which over 30 people died.

In Al-Zoubi’s opinion, the goal of Wednesday’s “collateral” reports about the alleged chemical attack by government forces was to undermine the work of UN investigators who arrived in Syria after receiving a request from Damascus.

If the UN commission successfully completes its work, investigators will discover that chemical weapons were used in Khan al-Assal and that the Syrian army did not use such arms, the minister stated.